@catweazle Opera 12.17 still scores 100/100 in the Acid3 test, so Vivaldi did not do so well. This test was invented by Opera.

I've 100/100 with Vivaldi in default configuration, without extensions. Exists other tests, but all off them give similar results in Opera and Chrome (and more than Firefox, Safari o that thing that have Windows)

But it is not the purely technical results that differentiate Vivaldi from others and why I have chosen it as my main browser, but the possibilities and functions it offers, much more than Chrome, even if it is equivalent in speed and other aspects.